92 THE TOXINS OF THE HIGHER PLANTS AND ANIMALS. 



Calmette notes in the blood of tuberculous patients more than the normal 



Cobra Toxin amount of lecithin; for that reason their serum can be used in very small 



Activation in doses to activate the cobra hemolysin. By this means he has found it 



Tuberculosis, possible to attain a diagnostic reaction for tuberculosis. On examination 



of the blood of 177 tubercular individuals he has found: 



78 per cent, of positive reactions in the first stage of tuberculosis. 

 57 per cent, of positive reactions in the second stage of tuberculosis. 

 70 per cent, of positive reactions in the third stage of tuberculosis. 



Szaboky has confirmed these findings, but not enough control examinations of normal in- 

 dividuals or of other infections have been made to firmly establish the diagnostic value 

 of the test. 



The hemolysis of snake poison can be overcome or interfered with by the 

 addition of large amounts of normal serum, cholesterin, and small amounts 

 of snake poison serum. 



Much and Holzmann have recently described the so-called "Psycho- 



The Psycho- reaction" which can be explained thus Normal serum, when added to a 



reaction. mixture of cobra extract and human red blood-cells will not interfere 



with consequent hemolysis. If, however, the serum obtained is from 

 patients suffering from depressive mania, circular insanity or dementia pracox, and 

 added to the cobra extract and human red blood-corpuscles, the expected hemolysis does 

 not take place. One would naturally suppose that this fact would be employed for 

 clinical diagnosis, but unfortunately it has been generally proven by most authorities in 

 this line that it is altogether impossible to do so for the simple reason that it is not abso- 

 lutely specific. Bauer has found the same reaction with navel blood. It is probable 

 that the interference with hemolysis is brought about by an increase in the cholesterin 

 of the serum a possibility in diseases of the central nervous system more so than under 

 any other physiological or pathological conditions. 



In immunizing laboratory animals one cannot start, at the 



beginning at least, with inoculations of the unaltered snake 

 Immunity. 



poison. 



Phisalix and Bertrand begin by employing subcutaneous injections of a toxin heated to 

 75 C. and after two days use one-half of the minimal lethal dose of the unaltered toxin. 



Calmette weakens the cobra poison by the addition of an equal amount of i per cent, 

 gold chlorid, and after four such injections with increasing amounts at each time, the pure 

 toxin in very small doses is employed. 



In the same manner Calmette immunized horses and obtained highly 

 antitoxic sera. He tested the strength of these sera, as follows: 



1. Upon Rabbits. Each animal received an injection of 2 c.c. of the serum into the 

 vein of one ear, and after two hours i mg. of toxin into the vein of the other ear. A 

 control animal was similarly treated with toxin only. The latter animal died in a half 

 hour, while the former remained alive. 



2. Upon White Mice. Diminishing amounts of serum were mixed in test tubes, 

 with o.oooi gm. of toxin (in i per cent, solution) and the mixtures injected into the 

 mice. The greatest amount of serum which completely neutralizes the toxin must be 

 0.03 c.c. 



